Survey of novel influenza A (H1N1) infection and vaccination in dialysis facilities in the Tokyo Tama area

The prevalence of novel influenza A (H1N1) and vaccination status in hemodialysis facilities were surveyed in the Tokyo Tama area. Using the network for disaster of the Santama Associations of Kidney Disease Physicians, novel influenza A (H1N1) infections among dialysis patients and staff of dialysis facilities were reported monthly between 1 October 2009 and 31 March 2010, and vaccinated subjects among dialysis patients and staff were also reported between 1 November 2009 and 31 March 2010. Seventy-six of 93 corresponding facilities participated in this survey. Prevalence of novel influenza A (H1N1) among dialysis patients and dialysis staff decreased gradually between October 2009 and March 2010. In 6 months, 70 dialysis patients and 25 dialysis staff were reported as having novel influenza A (H1N1) infection. The prevalence of influenza A (H1N1) among dialysis patients and dialysis staff was 1.58% and 2.59%, respectively. Only one dialysis patient required mechanical ventilation, but he eventually recovered. There were no deaths associated with novel influenza A (H1N1) among dialysis patients in this area. Dialysis patients aged 65 and over comprised 34.3% of infected cases. The positivity rates found using an influenza rapid diagnosis kit were 40% among dialysis patients and 60% among staff. Overall prevalence of novel influenza A (H1N1) in the general population was reported to be one-sixth in Japan. Our data on the prevalence in dialysis facilities were much lower than the estimates in the general population. This is mainly explained by the higher age composition of our subjects, especially among dialysis patients. In conclusion, the survey of novel influenza A (H1N1) and information sharing are useful for regional infection control at dialysis facilities.